the _Voice_, yet are they chiefly serviceable to it, in rendering it
to be more flat, and more sharp, and that especially by the _Bone of
the Tongue_, and the adjoyning Muscles: But I am unwilling to put from
this Office the Muscles which are proper to the _Wind-pipe_; for they
all unanimously conspire to make the _Cleft of the Throat_ either
wider, or narrower. But above all, here is that wonderful Faculty of
modifying the _Voice_, according to Will and Pleasure; which, even as
_Speech_ also, is not natural to us, but a Habite, contracted by long
Use or Custom. Hence it is, that the Unskilful are not only Ignorant
how to Sing, but also cannot so much as imitate others who are
Singing; so also such as are ignorant of any Language, do not only not
understand others who are speaking that Language, but also do not know
how presently to repeat that _Voice_ which they received by their
Ears.

Things principally requisite to the _Voice_, are, that the
_Wind-pipe_, the former thereof be solid, dry, and of the nature of
_Resounding_ Bodies. By this _Hypothesis_, two of the most Eminent
_Phænomena's of the Voice_ are discovered; why the _Voice_ should then
at length become firm and ripe, when the Bones have attained unto
their full Strength, and due Hardness, which cometh to pass much about
the Years of ripe age, when the vital Heat, doth in a greater degree
exert itself: The other Phænomenon is _Hoarsness_ or an utter loss of
the _Voice_, which is, when the _Cartilages_, or _Gristles of the
Throat_, especially the _Epiglott_, or Coverlid of the _Wind-pipe_, is
lined or besmeared all over with a slimy Viscosity, whereby they lose
their _Elasticity_, or Springiness. Now these Symptoms of the _Voice_
are also common to other _Wind-instruments_, when they become too much
moistned by any vapourous wetting Air. The same reason also is to be
assigned why the _Voice_ doth at last quite cease in those who have